Method of preparation of sulphamic



Unite States Patent METHOD OF PREPARATION OF SULPHAMIC AROMATIC ACIDSRobert Lazare Lantz, Paris, and Gilbert Henri Victor Kremer, Ermont,France, assignors to Compagnie Francaise des Matieres Color-antes,Paris, France, a French body corporate No Drawing. Application September21, 1954, Serial No. 457,536

Claims priority, application France October 5, 1953 4 Claims. (Ci.260-500) It is known that the reaction of 4-nitroso-phenyl-aminobenzenewith sodium sulphite yields an N-phenyl-diaminobenzene sulphonated inthe nucleus (Frankel and Spiro G. P. 775.36 Friedlaender 4 p. 87). It isto be noted that in the foregoing method of Frankel and Spiro a solutionof the nitroso derivative in an excess of caustic 'soda is used.

It has now been found that if the said nitroso derivative is treatedwith a salt of sulphurous acid, in the absence of caustic alkali and ina medium capable of dissolving at least partially, one of the twostarting materials, there is formed equally a sulphonated derivative of4-amino-diphenylamine but one in which the sulphonic group is found onthe primary amino group; the reaction has brought about thetransformation of the nitroso group N of the primary material into anamino-sulphonic group -NHSO3H. It has further been found that thislatter reaction is general, and that it allows of obtaining derivativessulphonated on the primary nitrogen of the 4-amino-diarylamines,starting from the 4-nitroso-diarylamines.

Amongst the para nitrosated diamine's to which the present processapplies may be mentioned those derived from symmetrical or unsymmetricalaryl amines, in particular 4-nitroso-diphenylamine, 4-nitroso-33-dimethyl-diphenylamine, 4-nitroso 3-methoxy-diphenylamine, and4-nitroso- 4'-Inethoxy-diphenylamine.

Examples of salts of sulphurous acid which may be used are in particularthe water soluble salts of this acid, like the alkali salts and thesalts of nitrogen bases.

The medium is considered to be free from caustic alkali if the totalityof the salts and other ionisable products which it contains, containsfewer equivalents of alkali metals than equivalents of acids, theinitial nitroso derivative not being reckoned as an acid.

It alkali salts of sulphurous acid are alone used, it is advantageous touse a bisulphite eventually mixed with a sulphite destined to change thepH of the medium, for this purpose another alkali salt can also be addedto the solution on condition of not introducing caustic alkali. Amongstthe salts of nitrogen bases which may be used, can be mentioned those ofammonia, of aliphatic, primary, secondary or tertiary amines such asmonodi, and trime'thylamine, di-ethylamine, aromatic amines such asaniline, heterocyclic bases such as pyridine, its homologues ortechnical mixtures containing these products. There can moveover be usedthe mixture of several salts of sulphurous acid, for example, themixture of an alkali salt and of a salt of a nitrogen base of this acid.

It has also been found that in many casesthe yields are improved byadding to the reaction medium nitrogen compounds. Amongst these may bementioned the bases mentioned in the forgoing paragraph and amides suchas formamide. The salt forming nitrogen bases can therefore occur in thereaction medium, in part in the state of salts of sulphurous acid, andpartly in the free state. It must 2,803,648 Patented Aug. 20, 1957 2 benoted that the presence of these bases in the free state does not supplycaustic alkalinity to the medium. The foregoing nitrogen compounds maybe used singly or in admixture.

Besides the foregoing products there may be added organic solvents suchas methyl, ethyl, propyl and butyl alcohols. There can even be used asreaction medium solely alcohol.

The sulphamic acids obtained are valuable materials for the dyestuffsindustry, or for the industry of dying fabrics and in particular for thepreparation of oxidation dyestuffs on the fibre.

The following examples in which the parts indicated, in the absence ofindications to the contrary, are parts by weight will illustrate theinvention without limiting it.

Example 1 There is added 100 parts of nitroso-4-phenylaminobenzene in amixture heated to C. and. agitated containing 142 parts of ammoniumsulphite in solution in 1000 parts of water and 1500 parts by volume ofethyl alcohol. The same conditions are maintained for 2 hours, then 110parts of anhydrous sodium carbonate are introduced, and the alcohol andpart of the water is distilled off. To the solution obtained, brought toa volume of 1000 parts, parts of sodium chloride are added and theprecipitate formed separated by filtering at 15-20 C. The product thusobtained consists of the sodium salt of N'-phenyl-1:4- diaminobenzene-N-sulphonic acid.

A similar result is obtained by replacing the solution of ammoniumsulphite by a similar solution containing an equimolecular quantity ofdi-ethylamine-sulphite.

Example 2 a half 75 parts of carbonate of sodium are introduced,

after which the pyridine is distilled off. The mixture is diluted to avolume equal to 1000 parts and is salted with 200 parts of sodiumchloride. The sodium salt of N phenyl-l:4-diaminobenzene-N -sulphonicacid precipitated, is filtered.

By operating in the same manner with 4-nitroso-3:3'-dimethyl-diphenylamine, there is obtained the sodium salt of N (3-methyl-phenyl)-1:4-diamino-3-rnethylbenzene- N -sulphonic acid whichafter crystallisation. in water and alcohol, forms small cleat greyishblue plates. Hydrolysed by boiling dilute hydrochloric acid andacetylated they yield 4acetylamino-3 :3'-dimethyl-diphenylamine of M. P.147 C.

The use as starting material of 4-nitroso-3-methoxydiphenylamine yieldsthe sodium salt of N -phenyl-1:4- diamino-3-methoxybenzcne-N sulphonicacid. The product recrystallised from a mixture of Water and alcoholconsists of pale bluish flakes. By hydrolysing the product 1 Example 3In a boiling mixture of 100 parts of 50% ethyl alcohol Example 4 Thereis heated to 80 C. the mixture formed by 66 parts by volume of asolution containing 370 g. per litre of ammonium sulphite, 14 parts ofwater and 73 parts of pyridine, then there is added thereto in 10minutes 20 parts of 4-nitroso-diphenylamine. After having further heatedthe mixture for 1 hour to the same temperature it is treated as in theforegoing examples. There is thus obtained a precipitate of the sodiumsalt of N -phenyl-1 :4- diaminobenzene-N -sulphonic acid.

The same compound may be prepared by operating in a like manner, butreplacing the pyridine by the same volume of formamide.

Example 5 There is introduced progressively parts of4-nitrosodiphenylamine into a mixture heated to boiling and stirred,containing 16.8 parts of ammonium sulphite crystallised with onemolecule of water in suspension in 50 parts of absolute alcohol. Theboiling is kept up till the disappearance of the yellow colour of thenitroso-derivative then 10.6 parts of anhydrous sodium carbonate isadded and 100 parts of water, and the organic solvent distilled off. Thesolution obtained is diluted to a volume equal to.75 parts, it is saltedout with 10 parts of sodium chloride and the precipitate of the sodiumsalt of N -phenyll:4-diaminobenzene-N -sulphonic acid filtered at C.

By replacing the absolute alcohol by the same quantity of the'azeotropic mixture of water and ethyl alcohol there is obtained a likeresult.

We claim:

1. A process for the preparation of a compound selected from thosehaving the following general formula:

in which'X and Y each represent a member selected from the groupconsisting of the hydrogen atom and the methyl and methoxy radicals,which comprises reacting, by heating between 70 C. and 100 C. a nitrosode' rivative selected from those having the following general formulamaterials.

2. A process for the preparation of a compound selected from thosehaving the following general formula:

4 in which X and Y each represent a member selected from the groupconsisting of the hydrogen atom and the methyl and methoxy radicals,which comprises reacting, by heating between 70 C. and 100 C., a nitrosoderivative se- 5 lected from those having the following general formula:

in which X and Y have the same significance as above, with a salt ofsulphurous acid selected from the group consisting of the alkali metalsalts and the nitrogen base salts, in the absence of caustic alkali, andin the presence of water and a free nitrogenous base.

3. A process for the preparation of a compound selected from thosehaving the following general formula:

in which X and Y have the same significance as above, with a salt ofsulphurous acid selected from thegroup consisting of the alkali metalsalts andthe nitrogen base of water and a water-miscible organicsolvent.

4. A process for the preparation of a compound selected from thosehaving the following general formula:

in which X and Y each represent a member selected from the groupconsisting of the hydrogen atom and the methyl and methoxy radicals,which comprises reacting, by heating between 70 C. and 100 C., a nitrosoderivative selected from those having the following general formula inwhich X and Y have the same significance as above, with a salt ofsulphurous acid selected from the group consisting of the alkali metalsalts and the nitrogen base salts, in the absence of caustic alkali, andin the presence of an alcohol.

References Cited in the file of this patent UNITED STATES PATENTS2,637,743 Lantz et a1. May 5, 1953 FOREIGN PATENTS 72,536 Germany a Oct.9, 1894 OTHER REFERENCES Lauer et al.: J. Amer. Chem. Soc., vol. 58,pgs. 225-.

salts, in the absence of caustic alkali, and in the presence.

1. A PROCESS FOR THE PREPARATION OF A COMPOUND SELECTED FROM THOSEHAVING THE FOLLOWING GENERAL FORMULA: